PUKING HEADS, Vent valves puking oil |
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PUKING HEADS, Vent valves puking oil |
GBallantine |
Jun 30 2005, 05:13 AM
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#1
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Member Group: Members Posts: 74 Joined: 12-October 04 From: Toronto,Ont.Canada Member No.: 2,930 |
My 914/4 vintage racer is not well and has 2 serious health problems.
1. after completely rebuilding my 2 litre motor with all new parts (nothing spared) I ran 1 overflow line from the canister and 2 head vent lines to an overflow bottle which collects approx a quart of oil/ 20 minute session on the track. I replaced the first set of rings after a leak down test revealed 36% to 70% leakage with a second set of custom made Total Seal rings . The same problem blow by. Any fix? 2.Oil temps are running at 280 plus. I run an additional cooler under the rear trunk with no results. Do any of the racer guys have any positive results when using the cooler fan units? Which units work the best? I know the best setup is the front mounted cooler but there's an issue with the 4 cyclinder oil pump not being able to supply a front cooler.I don't want to go to a dry sump setup. Suggestions needed, have to be ready for the next event at Beaverrun in Pittsburgh by July 8th. |
groot |
Jun 30 2005, 06:53 AM
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#2
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Dis member Group: Members Posts: 896 Joined: 17-December 03 From: Michigan Member No.: 1,444 |
OT is way high. I ran at M-O with 95 degree heat and high humidity and my OT only got to 225.
Let me ask some basic questions.... please don't be offended. Where's your cooler? Do the lines to and from the cooler warm up with the engine? Do you have a check valve? Is it installed correctly? What weight oil are you using? It certainly sounds like you're pressuring your valve covers or engine case, which says rings or valve seals. |
SLITS |
Jun 30 2005, 07:01 AM
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#3
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
I vote for the rings not seating due to:
1.) poor crosshatch on the cylinder walls (meaning not correct for the ring material) 2.) Seating procedure didn't work 2.) barrels are ovaled |
groot |
Jun 30 2005, 07:07 AM
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#4
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Dis member Group: Members Posts: 896 Joined: 17-December 03 From: Michigan Member No.: 1,444 |
Okay, but wouldn't that pressurize the case?
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Mark Henry |
Jun 30 2005, 07:16 AM
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#5
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Total seal rings are "total" garbage in a T4.
You've already warped your cylinders...new rings won't help. With those temps I’d say it’s been running lean (or too much advance) right from the start. If the oil system is done right a front cooler is no problem. |
groot |
Jun 30 2005, 07:29 AM
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#6
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Dis member Group: Members Posts: 896 Joined: 17-December 03 From: Michigan Member No.: 1,444 |
I am missing something here. If the heads are puking oil, why do you think his cylinders are warped?
Oh, yeah, I don't run a fan, but do run a single front mounted oil cooler (it's a Mocal about 8" by 10" or so) and an accumulator. |
Mark Henry |
Jun 30 2005, 08:20 AM
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#7
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
The case is being pressurized by something...
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davep |
Jun 30 2005, 08:23 AM
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#8
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914 Historian Group: Benefactors Posts: 5,151 Joined: 13-October 03 From: Burford, ON, N0E 1A0 Member No.: 1,244 Region Association: Canada |
If he has a lot of blowby due to warped cylinders / bad rings, then the crankcase is pressurized. That means the oil does not return down the pushrod tubes, and gets puked out the head vents.
I cannot see the cooler residing under the trunk. No airflow and high heat conditions in there. |
groot |
Jun 30 2005, 08:33 AM
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#9
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Dis member Group: Members Posts: 896 Joined: 17-December 03 From: Michigan Member No.: 1,444 |
Now that makes sense. Thanks!!!
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GBallantine |
Jun 30 2005, 09:30 AM
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#10
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Member Group: Members Posts: 74 Joined: 12-October 04 From: Toronto,Ont.Canada Member No.: 2,930 |
Thanks everyone for your comments. I used Deves rings in my first rebuild which led to the shitty leak down test of 36% to 70%. The motor came out after only 1 F@#$K race . The second rebuild I used the custom fit Total Seal rings and seated them properly on dyno oil 20 W 50. I ran this past weekend and detroyed the rear main bearing. I assume this was a result of the high temps.I pulled the motor on Tues to find no damage to the cyclinders ,cam,pistons,rods or crank only the bearing. What can be pressurising the the heads to this degree and causing the extreme blow by?
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Dave_Darling |
Jun 30 2005, 10:06 AM
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#11
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
I only know of one or two people who have actually gotten Total Seal rings to seat properly on our engines. I believe that Hastings rings are the good'uns to use now--though Brett W and Jake know a whole lot more about it than I do. IIRC, Deves used to make quality rings and now their QC has slipped. (I may be thinking of another company though.)
Blowby could be causing the oil pukeage. It could also be something as simple as windage throwing the oil into the head on the one side of the motor, or oil slosh from cornering. Go front-mounted on the oil cooler. It's the absolute best way to go on a race car--period. You can blueprint the stock oil pump and get reasonable delivery out of it, or you can go with the Schadeck Type I pump. I think the big'un has 30mm gears in it. Lotsa delivery there. You have to modify the pump, plus the cam gear, to make it fit right and work right. Talk to Raby about that; he does it all the time. These problems have been solved before. --DD |
Brando |
Jun 30 2005, 10:09 AM
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#12
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BUY MY SPARE KIDNEY!!! Group: Members Posts: 3,935 Joined: 29-August 04 From: Santa Ana, CA Member No.: 2,648 Region Association: Southern California |
Try Hastings rings next time.
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Jake Raby |
Jun 30 2005, 10:58 AM
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#13
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
I wouldn't install total seal rings in my worst enemy's engine... The idea is good, but the materials that they use just don't jive with the expansion rates of our cylinders.
I have tried all different sorts of roughness averages plateau finishes and ring end gaps with no success- I have totally given up on total seals here. The problem with most pistons that are bought from people that didn't have to build their reputation by building engines primarily is they have no first hand experience with the part they are selling you- Here I have developed our own piston designs with the proper ring land widths, radial depths and land spacing to match the best piston rings available... For instance, Dave recommends using hastings rings above- BUT its a serious longshot that those rings will fit the pistons you have correctly. I use hastings for 75% of my rings but we had to design the piston to work with those rings. The pistons that you have that ran the Deves rings will only work with Grant rings more than likely and they ABSOLUTELY SUCK! This is because the seller grabs whats on the shelf instead of trying to furtther develop it- I am very familiar with those pistons. A few years ago the Deves rings were the best we had to work with. I made many recommendations to use them but since we have found a much better ring, matching piston and cylinder finishes through trial, error and testing. The deves ring is a very soft ring not intended for serious cylinder pressures or temperatures. Okay, enough of that rant on parts pushers and non developed, off the shelf, generic, problematic pistons/rings! Now... If you smoked the #1 main bearing chances are your end play was not adequate.. The factory numbers in the "Book" should be throw away here guys- those numbers are barely adequate for a bone stock engine. Can you take pics of that bearing and send them to me or post them? If so I can tell you what killed it. |
GBallantine |
Jul 13 2005, 07:23 AM
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#14
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Member Group: Members Posts: 74 Joined: 12-October 04 From: Toronto,Ont.Canada Member No.: 2,930 |
Jake,
Thanks for the info. Do you sell sets of Hastings rings for my 96mm JE pistons that will solve my blowby problem? If so how or where do I get them? GB |
Bleyseng |
Jul 13 2005, 08:11 AM
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#15
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Aircooled Baby! Group: Members Posts: 13,035 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
I thought Jake wasn't too happy with the JE pistons either.....
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Jake Raby |
Jul 13 2005, 08:19 AM
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#16
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
JE pistons are fine for Super Performance engines...
In street engines they have more oil consumption and rattle when cold. The KB pistons are a much better piston for Performance street engines, their hastings rings seat in 5 minutes and they never burn oil! Total Seals SUCK!!!!!!!!! |
brant |
Jul 13 2005, 08:59 AM
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#17
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914 Wizard Group: Members Posts: 11,632 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
you NEED a front mounted cooler.
change the oil pump and go the front mounted cooler route! buy a stock mounting, high volume pump I think there are 2 options out there now.. the melling and one I can't remember the name of... for about 80 bucks you can have high volume and high pressure... then running a front cooler is only a matter of plumbing and ducting... otherwise, your going to continue to have motor problems. |
jr91472 |
Jul 13 2005, 04:01 PM
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#18
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"I'm pacing myself sergeant..." Group: Members Posts: 1,205 Joined: 2-August 04 From: McKinney, TX Member No.: 2,437 |
More great advice at no charge! Thanks for playing here Jake (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) |
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